Hi, Prologix arrived and working with John Miles, KE5FX software.

Hi,

POTY from 7470.exe .

Hi,

There are ground loops problems with Prologix Ethernet adapter. When connected ta a single device or alone there is no problem. But when multiple devices are connected via proper cabling the Ethernet stops to answer even to ping packets. The problem is not from the Ethernet connection. The problem is not always noticed. But when noticed even the ground connection of the GPIB cables is enought to make it stop working. Any advice is welcome ...

Hi,

Spectrum Surveillance Utility by John Miles, KE5FX worked via Internet. As it requires little BW its working fine remotely.

Quote from SV1BDS

Hi,

There are ground loops problems with Prologix Ethernet adapter. When connected ta a single device or alone there is no problem. But when multiple devices are connected via proper cabling the Ethernet stops to answer even to ping packets. The problem is not from the Ethernet connection. The problem is not always noticed. But when noticed even the ground connection of the GPIB cables is enought to make it stop working. Any advice is welcome ...

It seems that it is not a ground loop problem. It seems that one device when it is closed make the Prologix stop working.When the device is power up then Prologix works again.

Quote from SV1BDS

It seems that it is not a ground loop problem. It seems that one device when it is closed make the Prologix stop working.When the device is power up then Prologix works again.

Prologix answer:'For reliable operation, all devices connected to the GPIB bus must be powered ON even if they are not in use.'

Hi,

In order to measure drift of my Lars GPSDO compared to a Cesium reference I try the following setup: The two 10 MHz sources feed to an SBL1 mixer and IF output of this (DC capable output) feed to a 50 KHz LPF. The result is a very slow changing DC voltage of about +-200 mV. The voltage is change very slowly and it is impossible to measure time from 0 to 0. For example it take about 14 min for 0 to 0. Also the change is not at the same direction all the time. So I have to find a better aproach to measure such small frequency drifts. So I connected the AD8302 which measure phase difference. Its readings was in sync was the DC voltage output from the previous settup. The phase was changing slowly and worst change was about 1 degree per sec. Taking into accound that a circle has 360 degrees this leeds to think that the drift was about 2-3 mHz at 10 MHz. This looks like compatible with a previous measurment.

Quote from iw5bsf

Good morning George yesterday I remeasured the directional coupler 2.4 GHZ the only measures but with one hour of heating of the bolometer hp as the manual says good results 23 db of coupling and the directives 39 db what do you think

73 de iw5bsf Roberto

You have a difference of about 16 which is enought to measure SWR.

Hi,

As the directional coupler which is build some years ago it is good only for 1.2-2.4 GHz I try to build one for 5.9 GHz. The window is about 10 mm long by 1 mm wide. A margin of about 20 dB is available for measuring SWR.

Hi,

Overlapping the plots are more easy to see available working frequencies. It seems that the new one is suitable for 2.4,5.9,10 GHz.

Hi,

A non LNB Rx using a homebrew feeder, a small teflox coax, a surplus mixer and a surplus Lo at 10,345 GHz providing output IF at 144 MHz. A SNR of about 10 dB was archived. May be the IF output is small and need amplify.

Hi,

SNR improved still without lens at feeder. There is interference between 10 MHz reference and switching power supply.

PLL used with internal reference here.

Hi,

I measure 17 dB SNR with -130 dBm input at this system. Is this a real measurement or is fake? Have any one measure LNB sensitivity?

Hi,

I plan to create transverters for 2.4,5,10 GHz. Do you know any forum or list for technical discussion and schedule QSO ?

For 5,10 GHz I must take permission from local authorities. QO100 is a perfect back communication channel !!!

Hi,

The 10 GHz transverter is being beta tested.

1w @ 10368 GPSDO locked

IF 144 MHz

Rx image regection 45 dB

Tx Lo, image regection > 50 dB

Rx sensitivity -140 dBm for SSB (for 12 dB SNR)

Hi,

In order to do proper cabling for 10 GHz transverter for positive and ground cables I have some questions. For positive power a sequencer is usufull to protect coaxial relay from hot switched and PA from SWR during switching (in my case there is no problem as a circulator exists). For ground cabling is more complicated. There are three ground paths. One is the RF path via the semirigids between shielded boxes. The other one is the metal box that the elements are fixed. And finally the power path that provides power. The question is how to properly cabling it. The current of the PA is about 5 A. Any proposals are welcome !!!